The codex Parisino-petropolitanus is one of the earliest witnesses of the handwritten transmission of the Qur'anic text which has survived to this day. The various fragments which were part of the original manuscript are scattered among various collections; once put together, they provide a unique picture of the state of the text during the 7th century (orthography and textual peculiarities) and of the circumstances in which the canonical version as we know it today took shape physically. The present study, first of its kind, paves the way for a more accurate understanding of the beginning of Islam, based on a significant document, and of the evolution of the Qur'an during that period.